Announcement

Collapse
No announcement yet.

96 Prostar 350 TBI black smoke

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • 96 Prostar 350 TBI black smoke

    Last two times out I have started to notice black smoke at idle. It seems to get worse as the engine warms up. In the past the engine has always had a little white smoke at startup, but nothing like this. Motor isn't using any oil. I have also noticed a significant amount of black soot build-up above the swim platform. Motor is the standard 350 TBI. I have always thought that it has ran a little rich since I have owned it just based on the smell of the exhaust? Any help would be appreciated.
    -Aaron
    RED 1996 Prostar 205
    Indmar 350 TBI
    Acme 541
    PerfectPass Stargazer Wakeboard Edition

  • #2
    I'm not familiar with the EFI boats, but from an automobile perspective, I'd look at an O2 sensor or throttle position sensor. If one of those has gone bad (assuming the boat has them), that could cause a situation where the engine would run rich. O2 sensors are easy enough to replace on a car, it might be worth checking to find out if the boat has them.
    G

    Comment


    • #3
      Get a code reader for michigan motorz... will most likely show a code... $59ish bucks.
      sigpic...A bad day water skiing still beats a good day at work...1995 Pro Star 205....

      Comment


      • #4
        Mine was doing exactly the same thing. Same motor! Check the engine temp sensor as this will tell the computer the motor is cold and run it rich. They are cheap to replace,or you can test their resistance etc. I also replaced the 2 injectors as they were filthy. I have also now had them professionally cleaned and keep them as a spare.

        My money is on the temp sensor. It is the 2 wire unit out the top of the head near the throttle body sensor. Also when you replace it check inside the hole / head as mine also had a huge build up of muck arround the sensor which would not have helped either.
        Cheers

        Mark

        '99 Mastercraft ProStar 205 330-LTR

        Comment


        • #5
          Thanks for all the replies guys. Will check for codes and also look at the engine temp sensor. Would this sensor cause the ECM to throw a code?
          -Aaron
          RED 1996 Prostar 205
          Indmar 350 TBI
          Acme 541
          PerfectPass Stargazer Wakeboard Edition

          Comment


          • #6
            Originally posted by supturb89 View Post
            Thanks for all the replies guys. Will check for codes and also look at the engine temp sensor. Would this sensor cause the ECM to throw a code?
            It did not show any codes on mine, it was just reading about 15 degrees off when I tested it.
            Cheers

            Mark

            '99 Mastercraft ProStar 205 330-LTR

            Comment


            • #7
              Mark,

              Can you point me to where the engine temp sensor is. Is it in the throttle body? I'm not finding a 2-wire unit in the throttle body? There is a 3-wire sensor which I believe is the TPS and a 4-wire unit that I believe is the IAC. Am I looking in the right place? Thanks.

              Aaron
              -Aaron
              RED 1996 Prostar 205
              Indmar 350 TBI
              Acme 541
              PerfectPass Stargazer Wakeboard Edition

              Comment


              • #8
                should be in t-stat housing behind t-stat housing.... post a pic of the top of your engine without any covers on it.
                sigpic...A bad day water skiing still beats a good day at work...1995 Pro Star 205....

                Comment


                • #9
                  Aaron

                  It is not on the throttle body / manifold but it is on the same side of the head as the TPS ie Left if you face the rear of the boat. I have a great photo but the site does not seem to be uploading photos so I will try to explain.

                  On the left of the motor, it is installed verticaly downward from the top of the head. It is in the area behind the water pump / under the electronic gear/ to the right of the oil filler cap and slightly ahead of it. It has 2 wires to it White and Black which end in a black clip that clips onto the sensor.

                  You will use a LOT of fuel if this is faulty. I was running 2 to 3 tanks a day untill I fixed the issue ( multiple issues ). My boat looked like a diesel... and yes 2 families sking hard, at least 2 tanks a day so it was a priority to find the fault

                  If you want to test the OHMS resistance there is a thread of mine called "temp sensor resistance" (I think) that compares the resistance of my old unit / new unit and the factory spec.
                  Cheers

                  Mark

                  '99 Mastercraft ProStar 205 330-LTR

                  Comment


                  • #10
                    Mark,

                    Thanks for taking the time to write the detailed description, however I still can't find anything like what you describe in the area you describe. The only thing that comes close is a sensor below the exhaust manifold on the left side of the motor. It sits just above parallel with the spark plugs and sticks straight in. It has a black and yellow wire going to it (pic).

                    Here are some other pics of the area you are referring.

                    pic1
                    pic2
                    pretty sure this isn't it, but what is it????


                    Thanks again!
                    -Aaron
                    RED 1996 Prostar 205
                    Indmar 350 TBI
                    Acme 541
                    PerfectPass Stargazer Wakeboard Edition

                    Comment


                    • #11
                      That last picture is your knock sensor.

                      I'm pretty sure it is one of the two wires near the front of your engine on that first picture. I believe the one on right near the triangle (which is the t-stat) is the temp sensor for your dash. The one on the left is the temp sensor for the for the ECM. Not 100%, but think that is the case.

                      Comment


                      • #12
                        Thanks wtrskr,

                        I believe you may have them switched. The larger sensor on the left has been replaced when I was having issues with my temp gauge.
                        -Aaron
                        RED 1996 Prostar 205
                        Indmar 350 TBI
                        Acme 541
                        PerfectPass Stargazer Wakeboard Edition

                        Comment


                        • #13
                          I've always thought mine might run a little rich so I may test mine too. Let me know how you end up going about testing if you do. Mine throws no codes but I do get a little soot buildup just below and around the exhaust flaps.

                          If you want to test for codes, you don't need to buy a scanner. You just need a paper clip.

                          Does your dash have an engine temp light for warning of an overheat? If so, you turn the key to the ON position, engine OFF, then put the ends of the paperclip into terminals A and B of the code scanner thingy. It will start flashing the codes on your dash light. You can google paperclip and code reading.

                          Comment


                          • #14
                            Mark,

                            Thanks for the info on the engine coolant sensor. Changed it out today and the boat great with no black smoke. I didn't even have to wipe around the swim platform after pulling it out of the water!

                            wtrskr,

                            Before installing the sensor I tried the paperclip trick but my check engine light didn't flash anything at all, not even the code 12? I'm guessing that the light is not even hooked up for some reason. I have a "check engine" and "transmission temp" light on my dash. Are these supposed to light up at any time during start-up like in a car?

                            Thanks again gentlemen.

                            Aaron
                            -Aaron
                            RED 1996 Prostar 205
                            Indmar 350 TBI
                            Acme 541
                            PerfectPass Stargazer Wakeboard Edition

                            Comment


                            • #15
                              Originally posted by supturb89 View Post
                              Mark,

                              Thanks for the info on the engine coolant sensor. Changed it out today and the boat great with no black smoke. I didn't even have to wipe around the swim platform after pulling it out of the water!

                              wtrskr,

                              Before installing the sensor I tried the paperclip trick but my check engine light didn't flash anything at all, not even the code 12? I'm guessing that the light is not even hooked up for some reason. I have a "check engine" and "transmission temp" light on my dash. Are these supposed to light up at any time during start-up like in a car?

                              Thanks again gentlemen.

                              Aaron
                              Glad you got it fixed. Did you have the ignition key turned to the right when you tried it?

                              On my '94 I don't have a check engine light but there is another method to see the flashing. You take an led light (small trailer light or something like that) and you put the ends into, I want to say, terminals E and F. Those give the power for the led light. You don't want to screw up the terminals so I'd double check that somehow first. It can be a little tricky holding the paper clip and the led light at the same time.

                              Comment

                              Working...
                              X